1. Field of the Invention
The present invention relates to an electrically conductive foam component and, more-particularly, to an electrically conductive foam component for use as a toner supplying member, a transferring member, a developing member, a charging member, a sheet feeding and transporting member, a cleaning member or the like.
2. Description of the Art
Conventionally, a urethane foam or an elastomer foam is employed as a foam material for a toner supplying member, a transferring member, a developing member, a charging member, a sheet feeding and transporting member and a cleaning member. A quaternary ammonium salt is generally employed as an ion conductive agent to impart an electrically conductive property to the urethane foam and the elastomer foam.
However, a quaternary ammonium salt is not entirely compatible with a urethane polymer and an elastomer. Therefore, the foam material suffers from separation during storage thereof, so that the resulting product suffers from blooming over time and has an unstable electrically conductive property. Hence, there is a need for re-dispersing the quaternary ammonium salt in the material for the production of the product.
In view of the foregoing, it is an object of the present invention to provide an electrically conductive foam component which is free from blooming and has a stable electrically conductive property.
According to the present invention to achieve the aforesaid object, there is provided an electrically conductive foam component produced by foaming an electrically conductive composition which comprises a base-polymer and a borate compound represented by the following general formula (1): 
wherein R1 and R2, which may be the same or different, each represent a hydrogen atom, an alkyl group or an aryl group; M is an alkaline metal or an alkaline earth metal; and n is a positive number.
The inventors of the present invention conducted intensive studies on an electrically conductive composition to provide an electrically conductive foam component which is free from blooming and has a stable electrically conductive property. The inventors further conducted studies, focusing on a borate compound which is not generally used for ion conductive applications. As a result, the inventors found that the borate compound is slightly inferior in electrical conductivity to a quaternary ammonium salt, but a product produced by foaming a borate-containing composition has a stable and practically acceptable electrically conductive property (107 to 1010 xcexa9xc2x7cm), and that the borate compound is highly compatible with a base polymer. Thus, the inventors found that an electrically conductive foam compound produced by foaming an electrically conductive composition comprising a base polymer and a borate compound represented by the aforesaid general formula (1) is free from blooming and has a stable electrically conductive property, and attained the present invention.